The present invention relates to intraoperative surgical probes useful in cancer surgery because of their ability to detect beta and/or gamma radiation and to provide, in the immediate area of the surgery, a signal indicative of proximity to, and therefore the location of, cancerous tissue. A preferred embodiment of the surgical probe of the present invention also provides a simultaneous visual image of the incision.
The use of intraoperative probes to assist surgeons in defining the boundaries of cancerous lesions during surgical procedures performed following the injection of the patient with a radiopharmaceutical such as positron labeled fluorodeoxyglucose (FDG), the glucose analog commonly used for Positron Emission Tomography (PET).
One of the most reliable techniques for the detection of cancerous tissue is Positron Emission Tomography (PET) which involves the injection of a surgical patient with fluorodioxyglucose (FDG), a glucose analog that is preferentially taken up by quickly metabolizing cells such as those in the heart, brain and, for current purposes, cancer sites. FDG emits positrons that have a short (xcx9c1-2 mm) free path in human tissue before decaying into 511 keV gamma radiation. PET imagers detect these photons and construct a 3-D image of the patient. While these devices are extremely useful, they are, unfortunately, very expensive and very large. Thus, while used in the early detection and localization of cancerous areas, they are of less use in the surgical excision of diseased tissue, because their size makes them far to cumbersome for use in a surgical setting.
A highly desirable surgical probe would therefore be one of sufficiently small size as to truly be an intraoperative probe, which is capable of detecting beta, i.e. positron, emissions from a preferentially metabolized radiopharmaceutical such as FDG. Such a probe that could also selectively detect the 511 keV decay products of positrons would have even further enhanced capabilities for guiding a surgeon to the area of a cancerous lesion using the gamma emissions, and then zeroing in on its exact location, i.e. within about 1-2 mm, using the positron emissions as his/her guide.
U.S. patent application Ser. No. 09/240,239 filed Jan. 30, 1999 describes an intraoperative surgical probe capable of detecting both positrons and gamma-rays that preferably also incorporates visual and/or audible display mechanisms therein such that in the course of a surgical procedure the surgeon does not have to remove his/her eyes from the area of the incision to obtain information regarding proximity to the area identified for excision.
The just-described probe does not, however, provide any visual information regarding the physical structure or condition of the actual area of the incision, information that is equally useful and necessary to the surgeon and which, until now has only been available to the surgeon by observation of the incision directly with his or her eyes during the procedure. This condition often requires a larger incision than would be necessary to provide the required area of direct observation.
A device that incorporated the ability to acquire both directional information and provide a visual view of the internal area of the incision would therefore be highly desirable.
It is therefore an object of the present invention to provide an intraoperative surgical probe that provides directional information regarding the location of a lesion or other tissue to be removed to the surgeon in the handle or some portion thereof in the immediate vicinity of the incision while also incorporating the ability to provide visual information regarding the physical condition of the area of the incision simultaneously without the need for the surgeon to move or relocate the directional probe.
According to the present invention, there is provided an intraoperative surgical probe that combines an optical camera and a directional beta/gamma directional probe into a single unit. The leading end of the probe is optically coupled to a CCD camera in the trailing end of the probe by optical fibers located in the center of the probe. Scintillators located in the leading end and surrounding the centrally located imaging optical fibers are connected via light guides or separate optical fibers or rods to photodetectors located in the trailing end of the probe that also incorporates electronics to determine the directional location of the principal sources of radiation relative to the leading end of the probe and a display mechanism for communicating this information to the surgeon. Optical or visual information regarding the incision is communicated via the CCD camera and appropriate cabling to a video monitor in the immediate vicinity of the surgeon to simultaneously communicate the visual information.